Shocking video shows how violent Paris protests have become

Protesters in Paris have been condemned after footage emerged of people dropping large rocks off a bridge onto a busy road, smashing a car windscreen.

The footage, uploaded to YouTube by user Bobby Lapointe today, purports to show anti-Uber protesters in the French capital crowding a bridge over a road.

As a black car emerges from under the bridge, one man throws a large rock down, cracking the windscreen but fortunately bouncing off.

The car pauses and then speeds along the road to cheers from the protesters.

The riots in Paris, led by cabbies against ride-booking app Uber, earlier turned violent as cars were torched, roads were blocked and American rocker Courtney Love was attacked in her car.

Among the 2800 cabbies who took part in the strike, police have arrested at least 11 across the country in connection with confrontations that erupted as the drivers blocked access to airports, train stations and major roads.

In a tweet, Love wrote that protesters "ambushed" her vehicle and "were holding our driver hostage". Kurt Cobain's widow appealed to the French president in another message, writing "Francois Hollande where are the f---ing police???"

Taxi drivers in France are furious over an Uber service called UberPOP, which puts customers in touch with private drivers at prices lower than those of traditional taxis.

Licensed cabbies say the service is endangering their jobs by flooding the market with low-cost drivers.

UberPOP has been illegal in France since January, but the law has proved difficult to enforce and the service continues to operate.

One private chauffeur, who said he did not work for Uber "or any other app" was dragged from his van by angry cabbies when he reached a blockade in the west of Paris.

They slashed his tyres, smashed a window and then set it and another van on fire.

Police eventually fired tear gas and broke up the protest on the western stretch of motorway, clearing burning tyres from the road that rings the capital, but there were later attempts to stall traffic.

Officers arrested at least eight cabbies in Paris and near its airports in connection with the violence. Another three drivers were taken into custody in the southeastern city of Lyon.

Interior Minister Bernard Cazenueve called on "all those who are involved in the protests to not engage in any violence," and said he had told prosecutors to bring a prohibition order against the UberPOP service.

Peaceful protests played out at transport hubs in other major cities including Toulouse and Marseille. But traffic was backed up on roads around the country and travellers missed flights at major airports like Charles de Gaulle in Paris due to the protests.

US-based Uber, which offers several types of ride-sharing services, claims to have 400,000 UberPOP users in France. However, the drivers do not pay taxes, do not undergo the 250 hours of training that is mandatory for cabbies and do not carry the same insurance as taxis.